Microwave and vacuum drying device, system, and related methods

ABSTRACT

A method for drying at least one sample of material is provided. The method includes placing the at least one sample of material into a chamber and then sealing the chamber. The method includes applying a vacuum to the chamber in order to reduce the pressure therein. The method includes heating the at least one sample using electromagnetic energy while applying the vacuum to the chamber. The method includes measuring at least one condition of the chamber and determining that the sample is dry based on the at least one monitored condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/400,397, filed on May 1, 2019, which is a continuation of U.S. patentapplication Ser. No. 16/154,968, filed on Oct. 9, 2018, which claimspriority to U.S. patent application Ser. No. 14/214,630 filed on Mar.14, 2014, which claims priority to U.S. Provisional Patent ApplicationNo. 61/785,524, filed on Mar. 14, 2013, the entire contents of which areincorporated by reference herein.

TECHNICAL FIELD

This disclosure is directed towards a microwave and vacuum dryingdevice, system, and related methods.

BACKGROUND

Asphalt cores are removed from a road surface for subsequent testing inorder to determine the structural characteristics of the road surface.One such characteristic is the density of the road surface. This isparticularly important because of the granular and aggregate makeup ofpaving materials, which can have voids and other gaps that impact thestructural integrity of the road surface.

Due to the interconnected voids and gaps found in an asphalt core, andthe moisture content trapped within the voids due to the environment orcore extraction process, it is important to remove the moisture from theasphalt core in order to determine a dry density or other mechanistic orvolumetric parameter thereof. Removing the moisture content can be timeconsuming. One could air dry the core, but doing so would take anunacceptably long time. One could apply heat to the core, but doing socould cause unintended consequences to the core integrity. Previousattempts to dry cores involved lowering the pressure surrounding thecore. This results in rapidly lowering the sample temperature through anevaporation process. Relying exclusively on heat conduction from asupport or plate, or typical convection methods is not a reasonablesolution; as with a vacuum process, convection does not exist. InfraredRadiation heats only the surface of the sample or core, thus furtherrelying on the conduction of heat energy from the surface to graduallyheat the center or volume of the sample. By incorporating RF, RFinduction, or microwave sources, a substantial volume of the core orpavement material is instantly filled with energy, thermally inducingevaporation and drastically reducing time to remove the moisture.

A need therefore exists for a method or solution that addresses thesedisadvantages.

SUMMARY

This Summary is provided to introduce a selection of concepts insimplified forms that are further described below in the DetailedDescription of Illustrative Embodiments. This Summary is not intended toidentify key features or essential features of the claimed subjectmatter, nor is it intended to be used to limit the scope of the claimedsubject matter.

Disclosed herein are one or more microwave and vacuum drying systems,devices, and methods for drying asphalt samples, cores, aggregates,soils and pavement materials. Obtaining the moisture content of a soilquickly in the field or laboratory is also desired.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofpreferred embodiments, is better understood when read in conjunctionwith the appended drawings. For the purposes of illustration, there isshown in the drawings exemplary embodiments; however, the presentlydisclosed invention is not limited to the specific methods andinstrumentalities disclosed. In the drawings:

FIG. 1 is a perspective view of a sample drying system according to oneor more embodiments disclosed herein;

FIG. 2 is a front view of a sample drying system according to one ormore embodiments disclosed herein;

FIG. 3 is a side view of a sample drying system according to one or moreembodiments disclosed herein;

FIG. 4 is a perspective view of a sample of material to be tested withthe one or more drying systems disclosed herein;

FIG. 5A illustrates a waveguide installed in proximity to the one ormore drying systems according to one or more embodiments disclosedherein;

FIG. 5B illustrates an unfolded layout of the waveguide of FIG. 5Aaccording to one or more embodiments disclosed herein;

FIG. 6 is a schematic view of a sample drying system according to one ormore embodiments disclosed herein;

FIG. 7 is a schematic view of a sample drying system according to one ormore embodiments disclosed herein;

FIG. 8 is a schematic view of a sample drying system according to one ormore embodiments disclosed herein;

FIG. 9 is a schematic view of a sample drying system according to one ormore embodiments disclosed herein;

FIG. 10 is a flowchart depicting one or more methods according to one ormore embodiments disclosed herein;

FIG. 11 is a flowchart depicting one or more methods according to one ormore embodiments disclosed herein;

FIG. 12 is a chart showing pressure as a function of time, as well asmicrowave energy input according to one or more experiments; and

FIG. 13 is a flowchart depicting one or more methods according to one ormore embodiments disclosed herein.

DETAILED DESCRIPTION

The presently disclosed invention is described with specificity to meetstatutory requirements. However, the description itself is not intendedto limit the scope of this patent. Rather, the inventors havecontemplated that the claimed invention might also be embodied in otherways, to include different steps or elements similar to the onesdescribed in this document, in conjunction with other present or futuretechnologies.

One or more systems 10 are generally designated throughout the drawings,and with particular reference to FIGS. 1, 2, and 3 . The system 10 isprovided for drying one or more samples of pavement material removedfrom a road bed, base, embankment, surface or conveyor. The system 10includes a sealable chamber 12. The sealable chamber 12 may include anenclosure 14 that defines an interior 16. Interior 16 may include racksor other support structures that allow for placement of multiple samplesof material if desired. The enclosure may include a seal 17 for sealingagainst a door 15 or other access feature. One or more racks may beprovided for allowing placement of multiple materials to be dryed withthe one or more systems disclosed herein.

The enclosure 14 may define an outlet 20 that is configured forcommunicating to a pump 22 as will be further described herein. Theenclosure 14 may additionally define an aperture 24 and an opening 25that are configured for communicating with one or more microwave sources26.

The pump 22 may be provided for applying vacuuming forces to theinterior of chamber 12 in order to reduce the pressure therein to aid inremoval of moisture within the sample of material as will be furtherdescribed herein. The microwave source 26 is provided for applyingheating to the samples interior of chamber 12 in order to aid in removalof moisture within the sample of material as will be further describedherein.

A wave guide 50 as is further described herein may be in communicationwith openings 25 and 26 in order to direct microwaves into the chamber12. The waveguide 50 is illustrated in FIG. 5A and FIG. 5B, in which thewaveguide 50 is operably coupled with opening 26. The waveguide 50illustrated includes a folded thin sheet of metal. The elbow of the waveguide will be defined in accordance to the side flange port 25, 26 ofthe microwave.

The sample may be an asphalt core 1, as illustrated in FIG. 4 . Alsodisclosed herein, sample may be loose aggregate, soil, concretecomponents, and other construction related materials. A load cell may bein communication with the interior of the chamber to aid in calculatingmoisture content, or dryness.

This is vacuum chamber inside microwave cavity. One or more alternateconfigurations of a system are illustrated in FIG. 6 . In thisembodiment, system 110 was used in one or more experimental test as willbe described herein. System 110 includes a container 112 to whichmicrowave energy 126 is introduced. An enclosure 114 may be providedthat is configured for being sealed and receiving a sample material 1therein. In one or more experiments, the enclosure 114 was a vacuumpycnometer made of low loss plastic, ceramic material or pyrex,available from any suitable provider, and while commercial embodimentsmay not employ a pycnometer, the pycnometer was suitable for the one ormore experiments herein. The pycnometer is separable about a portionthereof such that a construction material can be placed into theinterior and the portions re-engaged in a sealable configuration. A pumpor vacuum 122 provides pumping forces along a line 118 to the enclosure114, thereby applying a pressure or reducing the pressure to producevacuum therein to the sample 1. Fluid flow can go in either directionwith the proper valve configuration. The line 118 may be in furthercommunication with a water trap such as a cold trap 150 and a pressuregauge 130 that monitors the pressure in enclosure 114. Cold traps alsoaid the vacuum pumping process when removing air as they form cryogenicpumping forces in series or parallel to the pump 122. Water vapor andliquid is kept from going into the vacuum pump using any water removalmethod such as a cold trap, desiccant, centrifuge.

One or more alternate configurations of a system are illustrated in FIG.7 . In this embodiment, system 210 was used in one or more experimentaltest as will be described herein. System 210 includes a container 212 towhich microwave energy 226 is introduced. An enclosure 214 may beprovided that is configured for being sealed and receiving a samplematerial 1 therein. A pump or vacuum 222 provides pumping forces to theenclosure 214, thereby applying a pressure to induce fluid flow thereinto the sample 1. A sealing member 217 may be provided for providing apressure tight seal of the container 212. A sealing member may be o-ringor silicon.

One or more alternate configurations of a system are illustrated in FIG.8 that combines aspects of system 110 in FIG. 6 and system 210 in FIG. 7. In this embodiment, system 310 was used in one or more experimentaltest as will be described herein. System 310 includes a container orcavity 312 to which microwave energy 326 is introduced. An enclosure314, similar to enclosure 214, may be provided that is configured forbeing sealed and receiving a sample material 1 therein. A pump or vacuum322 provides pumping forces to the enclosure 314, thereby applying apressure therein to the sample 1. A sealing member 317 may be providedfor providing a pressure tight seal of the container 312 differentcontainers. The pump or vacuum 322 provides pumping forces along a line318 to the enclosure 314, thereby applying a pressure therein to thesample 1. The line 318 may be in further communication with a cold trap350 and a pressure gauge 330 that monitors the pressure in enclosure314. One or more alternate configurations of a system are illustrated inFIG. 9 that combines aspects of system 110 in FIG. 6 and system 210 inFIG. 7 . In this embodiment, system 410 was used in one or moreexperimental test as will be described herein. System 410 includes acontainer 412 that defines a cavity to which microwave energy 426 isintroduced. An enclosure 414, similar to enclosure 214, may be providedthat is configured for being sealed and receiving a sample material 1therein. A pump or vacuum 422 provides pumping forces to the fluid flowof the enclosure 414, thereby applying a pressure therein to the sample1. A sealing member 417 may be provided for providing a pressure tightseal of the container 412. The pump or vacuum 422 provides pumpingforces along a line 418 to the enclosure 414, thereby applying apressure therein to the sample 1. The line 418 may be in furthercommunication with a cold trap 450, or a desiccant, and a pressure gauge430 that monitors the pressure in enclosure 414.

The microwave containment system can be the same as the vacuum cavity,or the vacuum cavity and microwave cavity can be separate. In one case,the vacuum cavity can be interior to the microwave cavity, on the otherhand the microwave cavity can be interior to the vacuum cavity, or onein the same. Multiple vacuum enclosures can be included such as wheneach sample has its own microwave transparent vacuum canister. A singlelarge vacuum chamber can contain multiple samples.

The one or more systems disclosed herein combine a pressure vacuum andan electromagnetic source in order to dry one or more samples. Theelectromagnetic source may be a microwave. Microwaves areelectromagnetic waves having wavelength (peak to peak distance) varyingfrom 1 millimeter to 1 meter (frequency of these microwaves lies between0.3 GHz and 30 GHz) and have greater frequency than lower frequencyradio waves so they can be more tightly concentrated. For lowerfrequencies, coupling of electromagnetic energy into the cavity may notbe possible, and large areas of the cavity may have dead spots or no RFenergy at all. If the frequency is too low, the cavity would behave as acapacitive load with no power delivered. Microwaves bounded by theinside of the conducting enclosure produce volumetrically high and lowenergy locations. This is caused by wavelength of the microwaves beingon the order of ½ the size of the cavity or less, or on the order of ½to 10 times smaller than the dimensions of the cavity offering manyelectromagnetic modes. Hence, constructive and destructiveelectromagnetic field configurations form and allow for uniformvolumetric heating of a sample. Even better uniformity of the microwaveenergy is accomplished using mode stirring, such as by rotating samples.This dynamically causes the field configurations interior to the cavityto dynamically change. Typical mode stirring can be accomplished using amechanical stirrer. Typical structures look like a fan with conductingblades that force different coupling modes into the chamber. Opticalsources such as infrared irradiative sources, do not have theseproperties as the cavity is millions of times larger than thewavelength. The principles guiding the physics on these large scales areentirely different. Infrared energy does not penetrate the surface morethan a few microns, and the sample surfaces are heated by heatconduction flow resulting from the temperature differential between thesurface and center of the sample. The microwaves, which inherently andinstantly penetrate to interior of the sample, result in the waterabsorbing the microwave energy and becoming heated within the core ofthe sample. The temperature of the water is increase, allowing fasttransfer of moisture out of the sample. Hence, microwave drying israpid, more uniform and energy efficient compared to conventional hotair drying. The problems in microwave drying, however, include productdamage caused by excessive heating due to poorly controlled heat andmass transfer. In this manner, the combination of a vacuum force and amicrowave source are used to counter balance each other. Here, on onehand, the vacuum reduces the pressure thus further evaporating the waterin the sample. This reduces sample temperature as water is evaporatedand removed. On the other hand, the microwave source is directed at thesample, whereby the microwave energy is absorbed increasing the thermalenergy of the water molecules; thus counteracting the cooling processfrom the forced evaporation. Hence the samples can remain at relativelyconstant temperatures throughout a drying process.

One or more methods are disclosed herein. Since the Microwaves will tendto heat and the Vacuum cool the pucks, the one or more methods hereinmay attempt to maintain the sample material at a constant temperature of20 degrees C. during the entire drying cycle. Conversely, the object isto not exceed a predetermined sample temperature such as 50 degrees C.The power or duty cycle of the microwave controller is adjusted inconcert with the pressure to regulate the temperature and pressure andmaximize mass transfer with the vacuum pump.

One or more sensors are in communication with the one or more systemsdisclosed herein to monitor one or more characteristics of the methodand process. The one or more sensors may include a temperature sensorthat measures the temperature inside of the containers described herein.The one or more sensors may be a thermocouple, a thermistors (PTC:Positive Temperature Coefficient/NTC: Negative), and an RTD ResistanceTemperature Detector (USA)/PT100 (Europe). Alternatively, an infraredbased measurement device, including an IR thermocouple. An infraredthermometer measures temperature by detecting the infrared energyemitted by all materials which are at temperatures above absolute zero,(0° Kelvin). The IR part of the spectrum spans wavelengths from 0.7micrometers to 1000 micrometers (microns). Within this wave band, onlyfrequencies of 0.7 microns to 20 microns are used for practice, becausethe IR detectors currently available to industry are not sensitiveenough to detect the very small amounts of energy available atwavelengths beyond 20 microns. Infrared Thermocouples (IRt/c's) have aninfrared detection system which receives the heat energy radiated fromobjects the sensor is aimed at, and converts the heat passively to anelectrical potential. A millivolt signal is produced, which is scaled tothe desired thermocouple characteristics. Since some IRt/c's areself-powered devices, and rely only on the incoming infrared radiationto produce the signal through thermoelectric effects, the signal willfollow the rules of radiative thermal physics, and be subject to thenon-linearities inherent in the process. However, over a range oftemperatures, the IRt/c output is sufficiently linear to produce asignal which can be interchanged directly for a conventional t/c signal.For example, specifying a 2% match to t/c linearity results in atemperature range in which the IRt/c will produce a signal within 2% ofthe conventional t/c operating over that range. Specifying 5% willproduce a somewhat wider range, etc. The IRt/c is rated at 1% (ofreading) repeatability and to have no measurable long term calibrationchange, which makes it well suited for reliable temperature control.

The one or more methods disclosed herein are illustrated well in theflowcharts of FIG. 10 and FIG. 11 . As illustrated in FIG. 10 , a method1010 provides turning on the vacuum source, placing the sample materialinside of the enclosure, and shutting the door to seal the enclosure1012. As further described herein, each of the steps of 1012 may besimultaneously or subsequently provided. The method 1010 may furtherinclude providing vacuum forces for a defined period of time 1014. Thevacuum forces may be provided by the pumping systems disclosed herein.

The method 1010 may further include applying pressure through a vacuumforce until a desired pressure is reached 1016. This may be monitored byone or more pressure gauges disclosed herein. The method 1010 mayfurther include powering on the microwave source 1018. Microwave sourcemay be provided by the one or more microwave sources disclosed herein.

The method 1010 may further include determining if the temperaturemeasured is greater than 50 degrees C. 1022. If the measured temperatureis above 50 degrees C., meaning the temperature is approaching not beingrelatively constant throughout the drying cycle, then the microwavesource is stopped 1026. If the measured temperature remains below 50degrees C., then additional microwave energy may be applied or,alternatively, the microwave energy may be ceased and pressure held. Themethod 1010 may further include determining if the microwave cycle hasfinished 1024. This may be accomplished with reference to apredetermined microwaving period of time. If it is determined that themicrowave period of time is over, then the microwave is stopped 1026. Ifit is determined that that microwave period of time is not over, thenadditional microwave source is provided. Once the microwave is stoppedin either of 1026 or 1020, the mass constant is measured 1028 of thesample material. If it is determined that the sample is dry, then thesystem is stopped 1030. Dryness can be measured by weighing, humidityinstrumentation, or ultimate pressure. As long as water is evaporating,it is “out-gassing” and the ultimate pressure is not achieved. Tocalibrate, the ultimate pressure is measured without a sample, and isthe lowest pressure attainable after all water is pumped off the chamberwalls. Water is bound to the walls even in an empty chamber. In otherwords, the one or more methods include pumping (vacuum) an emptychamber, recording the minimum or best vacuum pressure obtained, whichin one or more experiments, may be about 2 or 3 Torr, placing the samplein the chamber and the method includes further pumping (vacuum) of thechamber containing the sample. The pressure will remain higher than theultimate pressure until all the water is evaporated. For this example,when the sample chamber reaches 2 or 3 Torr, it is dry.

One or more additional methods are illustrated in FIG. 11 and generallydesignated 1110. The one or more methods 1110 may include providing asample to be dried 112. The one or more methods 1110 may include sealingthe chamber to which the sample is in 1114. The one or more methods 1110may include providing a vacuum to the chamber 1116. The one or moremethods 1110 may include providing a microwave to the chamber 1120. Thestep of providing microwave 1120 may be carried out in a step-wisefunction or a duty cycle, meaning on again, off again in time thusobtaining the capability to adjust the average power delivered to thesample, as described in further detail herein. The one or more methods1110 may include determining if the ultimate pressure has been reachedin the chamber 1122. If the ultimate pressure has not been reached,additional gas, such as ambient, nitrogen, or helium can be added to thechamber 1124 for a specified time, at which point, the vacuum step 1116and microwave step 1120 begin again. If the ultimate pressure has beenreached, determine if the sample is dry 1126. If the sample is not dry,additional gas, such as ambient, nitrogen, or helium can be added to thechamber 1130, at which point, the vacuum step 1116 and microwave step1120 begin again. If the sample is dry, then the process is finished1132. Possible heating energy can be achieved by controlling the dutycycle as in FIG. 12 or by controlling the High voltage power supply ofthe magnetron to attain a specified percent of power.

One can tell when a sample is dry because the sample stops losingweight, or humidity sensor indicator, temperature stabilizes at zeromicrowave power, as microwaves counter balance the thermodynamic coolingof the sample, or ultimate pressure is obtained. The temperature of thesamples is monitored via IR thermocouple and a feed back and controlsystem keeps the microwave energy from heating the cores above a certainvalue, for example, 40 C, 50 C or 60 C.

Alternatively, a regular microwave oven could be used without theexpense of making it vacuum worthy. Then each porous sample that was tobe dried could be inserted into its own personal small vacuum chamberand placed into the microwave oven. Inside would be quick release vacuumhookups to reduce pressure for each individual sample. The microwavedisclosed methods and instrumentation would be then used to monitor eachsample separately, with feedback to a programmable computer to monitorand control microwave power directed to each sample. Alternatively, aneconomical microwave oven could be modified to accept a single vacuumcavity where one or more samples can reside for drying and monitoring.

Shrink Wrapping Cores and Aggregates Duel Use

Asphalt samples, cores, and aggregates may have a shrink wrap appliedthereon for sealing off the core from water intrusion during a volumedetermination method that uses water. For example, in one or moreembodiments, the volume of a core may be determined by submerging thecore in a water bath, and measuring the volume increase of the waterbath/core combination. Or the weight of the dry sample in air comparedto the weight submerged in a fluid or powder allows for the buoyancyeffects to calculate volume provided that the specific gravity of thefluid is known. However, for porous materials, water can infiltrate intovoids in the core and then the water is difficult to remove. Furthermoreand more importantly, water seepage to the interior of the core gives afalse mass reading in the water, thus resulting in an underestimate ofthe actual volume of the sample. In other words, if the core needs to besubsequently weighed in order to, for example, determine density of thecore, the infiltrated water impacts the accuracy of the weightmeasurement and the volume calculation.

A shrink wrap envelope may be applied to the core or pavement sample inorder to seal off the core interior while conforming to the complexshape of the surface features before the core is submerged in water. Theshrink wrap may be heated with microwave heating, infrared heating, orany other suitable heat source. A vacuum may also be applied. A slightor greater increase in pressure may also be used to make the shrink wrapmaterial flow into the pits and surface of the asphalt core and/oraggregates. For example, one or more shrink wrapping techniques may beemployed that are described in U.S. Pat. Nos. 6,615,643 and 6,615,643,the entire contents of which are hereby incorporated by reference.Shrink wrap material may be of a conformal shape to the sample such asin a cylindrical conforming shape, or it may be rectangular in shape andconform to the sample leaving excess material of negligible volume inthe finished sealing product.

The shrink wrap can be coated with a microwave lossy material such ascarbon or conductor or a semiconductor to increase the energy absorptionto the bag and more quickly shrink the plastic. Conversely, if theenvelope material is not a shrinkable polymer, forming the polymer tothe surface imperfections can be accomplished by heating the materialwhile applying vacuum or pressure cycles. The polymer or bag can bewrapped around the core and inserted into the vacuum chamber. Theprocedure may be to decrease pressure so that the bag adheres to thesurface, while applying energy to mold and shrink the bag.

A good vacuum at most can apply about 14 psi to the surface area of theshrinkable material. However adding positive pressure allows for muchhigher surface forces to be applied to the shrinkable bag. For example,14, 28, 42 or up to 100 psi can be applied easily. One possible methodfor sealing may include inserting a sample, pulling a good vacuum,heating the bag and sealing the bag, then bringing the system back toatmospheric pressure, and then adding air pressure to further set theshrinkable bag, while still adding microwave energy. IR energy couldalso be used to shrink the bag.

Once the vacuum has set the bag, a gas such as ambient air, or dry airor nitrogen could be added to the chamber to increase pressure. Positivepressures could be formed further pushing the polymer or bag into thesurface imperfections. Typical shrink bags tend to not form preciselyinto the imperfections, making the material sample look like it has alarger volume when the Archimedes principle or rather water bath is usedto determine volume or density. Adding positive pressure reduces thisnon conformal effect.

In another approach, convection principles only could be used wherebythe vacuum is made, then positive pressure is applied with respect toatmospheric pressure. This will help set the bag.

In general the samples in any case could rotate and spin in themicrowave vacuum oven. Turnstile tables are controlled inside themicrowave or vacuum chamber to the proper speed and position. Thesecould be rotated through hermitically sealed shafts, or through a windup mechanism. Several axes of rotation can be used. The turntables aremicrowave invisible and could be of a plastic, ceramic, or Pyrex® glass.

Experimental Results

The following experiments have been made using a microwave source inwhich a plastic vacuum chamber (pycnometer) has been placed interior tothe microwave oven. A hole is drilled on top of the microwave so that ahose connects the Vacuum chamber, the pumping installation and thepressure gage. This is illustrated schematically in FIG. 6 .

In early experiments, the pumping installation included a no water trapwhere the water evaporated directly in the vacuum pump, whereas latertests included a desiccant 450 illustrated in FIG. 9 and a cold trap 350illustrated in FIG. 8 . The plastic vacuum chamber included a sphericalshape sealed on bottom and top that was sealed with a silicon o-ring ora flat layer of silicon

In the one or more experiments, the vacillation of the Microwave and theVacuum, for example, a cycle during which the Microwave oven heats thesample only when the vacuum pressure is raised to a certain level, isadvantageous, namely, by letting “dry” air in the vacuum chamber. Heredry is in comparison to the chamber interior, mainly constituted ofwater vapor, The proportion of water vapor is decreased and thereforethe relative humidity becomes lower. As a result, the condensation ofwater vapor on the surfaces of the vacuum chamber, which increase theefficiency of the drying, is limited. When the vacuum is low enough,below about 10 T, the microwave electric fields strip electrons off theair and water molecules. At this low pressure, the mean free path of thegas molecules is long enough that the electrons can accelerate via the Efields and ionize another particle. Thus avalanche plasma was formed.This plasma aids in mode stirring and uniform heating as it becomesrandomly in the chamber. To control the plasma, either the electricfield is reduced, or the pressure is raised above the mean free path ofthe molecules. As the water vapor decreases and the samples become dry,exciting the plasma becomes less probable, and finally ceases to existbelow the pressure threshold of about 10 to 15 Torr.

Experimental Results I

In each of the following experiments, the system 110 disclosed in FIG. 6was used to test the drying process of asphalt cores (referred to as“pucks” in the industry), except the cold trap 150 was not employed.Tests were performed on small Marshall, larger Superpave pucks, and madeof coarse and fine aggregates, and the tests were carried out with andwithout microwaves. The microwave source was added with a controlledduty cycle according to the diagram of FIG. 12 . The duty cycle canadjust the average delivered power from 0 percent to 100 percent.

As illustrated in FIG. 12 , a cycle of eight minutes was used, withalternation of 1 minute of vacuum added (during which the microwave isnot being provided), and 1 minute of pressure increase (where microwaveis being provided). The pressure raise in these one or more experimentsapproached about 30 Torr.

Other uses include a portable field device for quick and accurate soilmoisture measurements.

Certain samples tested and experimental results of those tests aredetailed in TABLE I.

TABLE I Time to Final “fully” water dry the Vacuum Initial content puckTemperature level water after 8 (0.1 g or commonly commonly Puck contentminutes less left) reached reached Small 4 g to 0.1 g to 15 35° C. to 8to 11 Torr Aggregate, 7 g 0.5 g minutes 45° C. 1 kg to 1.5 kg Big AroundAround 15 35° C. to 8 to 11 Torr Aggregate, 4 g 0.3 g minutes 45° C. 4.8kg, low absorption Big Around 15 g to 25 40° C. to 8 to 11 TorrAggregate, 40 g 20 g minutes 50° C. 4.7 kg, high absorption

Certain samples tested and experimental results of those tests aredetailed in TABLE II.

TABLE II Time to “fully” dry the puck Mass (Absorption = Vacuum Initialof “8%” after 2 Temperature level water Soil consecutive commonlycommonly Soils content tested test) reached reached Sand Around 8% 250 g5 × 8 minutes = 30° C. to 8 to 11 Torr 40 min 60° C. Franken Around 8%250 g 4 × 8 minutes = Soil 32 min

Certain samples tested and experimental results of those tests aredetailed in TABLE III.

TABLE III Mass Final water Vacuum Initial of content Temperature levelwater Rocks after 8 commonly commonly Rocks content tested minutesreached reached Random 4 g to Around Around 30° C. to 8 to 11 rocks 5 g1 kg 0.3 g 40° C. Torr

The one or more experiments conducted herein were measured with respectto a vacuum only cycle and a vacuum with microwave cycle. Theexperimental results of those tests are detailed in TABLE IV.

TABLE IV Factor of Vacuum Cycle Only Vacuum + MW Cycles ImprovementInitial Final % water Initial Final % water due to the Cycle of 8 massmass pumped mass mass pumped Combined minutes of of (Mi- of of (Mi-cycle Vac + PUCK water water Mf)/Mi water water Mf)/Mi MW Small, fine5.4 3.2 40.74% 5.1 0.5  90.2% 121.4% Agg Small, 7.7 4.6 40.26% 5.4 0.2 96.3% 139.2% coarse Agg Big, low 4.6 0.7 84.78% 4.3 0.3   93%  9.69%absorption Big, high 35.1 22.6 35.61% 40 20.5 48.75%  36.9% absorption

The one or more experiments conducted herein were measured with respectto a vacuum only cycle and a vacuum with microwave cycle. Theexperimental results of those tests are detailed in TABLE V.

TABLE V Factor of Vacuum Cycle Only Vacuum + MW Cycles ImprovementInitial Final % water Initial Final % water due to the mass mass pumpedmass mass pumped Combined of of (Mi- of of (Mi- cycle Vac + PUCK waterwater Mf)/Mi water water Mf)/Mi MW Big, low 3.4 0.1   97% 5.2 0.1   98% 1% absorption Big, high 41.7 21.1 49.4% 40.8 10.4 74.5% 51% absorption

The one or more experiments conducted herein were measured with respectto a vacuum only cycle and a vacuum with microwave cycle. Theexperimental results of those tests are detailed in TABLE VI.

TABLE VI Factor of Vacuum Cycle Only Vacuum + MW Cycles ImprovementCycle of Initial Final % water Initial Final % water due to the 25 massmass pumped mass mass pumped Combined minutes of of (Mi- of of (Mi-cycle Vac + PUCK water water Mf)/Mi water water Mf)/Mi MW Big, high 41.75 88% 40.8 0 100% 13.6% absorption

The combined cycles are more than twice as efficient for small pucks(which can be dried quickly).

For bigger pucks (for which the drying last longer), the gain is not ashigh but still significant: 10% to 50%.

In these one or more experiments, where substandard results weredetermined, it was determined that this was mostly likely the cause ofan inability to hold vacuum or attain a quality vacuum due to vacuumleaks.

Experimental Results II

In this sets of experimental tests, the system 110 of FIG. 6 was used,including a cold trap 150 which included a microwave choke filter. Here,the choke is designed for safety to keep the microwaves from escapingthrough the vacuum aperture. In the one or more experiments, thismicrowave filter was a copper abrasive pad stuffed in the vacuum line tomake sure microwave energy would not leak into the room. The operatorrecords drying time, mass and temperature before and after each testing.

In addition the operator performs the MW/Vacuum cycles. That is to saythat the operator runs the pump, waits for 1 minute, turns the microwaveon while raising the pressure (manually through a button on top of thecold trap 150), and then turns the microwave off and lets the pressuredown in a cycle that may be later repeated. While in this experiment,the operator records the vacuum pressure read by the pressure gage 130.

This process is described in detail in the flowchart of FIG. 13 , withFIG. 12 illustrating the application of microwave energy and vacuumforces as a function of time. As illustrated in FIG. 13 , a method 1310is provided and used in these one or more experiments. The method 1310includes putting the sample in the vacuum chamber and the vacuum chamberin the microwave 1313 no see. The method 1310 includes running thevacuum pump 1314. The method 1310 includes waiting one minute (whilevacuum is held), and recording pressure 1316. The method 1310 includesturning the microwave on while pressing a button on top of the cold trapthat was in communication with a valve to allow a pressure increase toabout 100 Torr 1310. The method 1310 includes waiting about one minute,then recording the pressure 1322. The method 1310 includes turning offthe microwave and letting the pressure reduce 1324. The cycle is thenrepeated according to the flowchart. Dryness was usually determined bythe ability to attain a predetermined vacuum level such as the ultimatepressure.

In these one or more experiments, the test compared a conventionalasphalt drying unit with the one or more systems disclosed herein. Inorder to do so, the test compared the time necessary to dry the sampleas well as the quantity of water removed.

In order to quantify theses differences, an improvement factor (6%) wasdefined:

-   -   The Average mass of Water removed by the MW/Vac system (in        percentage), should be 6% more than the Average mass of Water        removed by the ADU: Y(MW−VAC)=(1+δ%)·X(ADU)    -   The Average time to dry a sample using the MW/Vac system (in        percentage), should be 6% less than the Average time to dry the        sample using the ADU: Y(MW−VAC)=(1−δ%)·X(ADU)

As far as performance of the large puck made of coarse graduates, animprovement was observed by the one or more systems disclosed hereinover the ADU because, while removing similar amounts of water, the oneor more systems disclosed herein accomplished doing so in about 25% lesstime than the ADU.

As far as performance of the small puck made of coarse aggregates,within the same drying period, the one or more systems disclosed hereinremoved about 20% more water.

As far as performance of the small puck made of small aggregates, theone or more systems disclosed herein did not perform as well as the ADU,which had twice the drying time, but also removed twice as much water.

As far as performance for rocks, the drying time with the one or moresystems disclosed herein was 75% less than the drying time for the ADU,however, the amount of water removed from the rocks was half of thatremoved from the ADU.

As far as performance for sands, the one or more systems disclosedherein were more efficient than the ADU.

As far as performance of water, the one or more systems disclosed hereinremove 99% of water, whereas the ADU removed less.

Additional Experimental Results

In the tables that follow, various experiments were conducted. In thesection of each respective table labeled “Equipment use,” the equipmentused and subject matter being tested is listed. Any relevant conditionsof experiment are listed in the “Conditions of experiment” section.

TABLE VII Equipment used Pump “Rice test” Chamber Pressure pirani gage#2 Small asphalt puck Conditions of Pumping by the top experimentPressure measurement by the side Pressure Measurement P1 chambre (torr)t (s)

0 800 5 400 10 50 20 16 30 14 40 13 50 12 60 11 70 11 80 11 90 11 100 10110 10 120 9.5 150 9 180 8.5 220 8 Minitial (g) 1097.8 Mfinal (g) 1095.2% loss [Mi- Mf]/Mi 0.24%

TABLE VIII Equipment used Pump “Rice test” Chamber Pressure pirani gage#2 Small concrete puck Conditions of Pumping by the top experimentPressure measurement by the side Pressure Measurement P1 chambre (torr)t (s)

0 800 5 250 10 50 20 17 30 15 40 14 50 14 60 13 70 13 80 13 90 12 100 12110 12 120 12 150 11 180 11 220 11 Minitial (g) 979.9 Mfinal (g) 977 %loss [Mi-Mf]/IV 0.30%

TABLE IX Equipment used Pump “Rice test” Chamber Pressure pirani gage #2Big asphalt puck Conditions of Pumping by the top experiment Pressuremeasurement by the side Pressure Measurement P1 chambre (torr) t (s)

0 800 5 90 10 20 20 15 30 14 40 13 50 13 60 13 70 12 80 12 90 12 100 11110 11 120 11 150 11 180 11 220 10 Minitial (g) 4822.6 Mfinal (g) 4818.8% loss[Mi-Mf]/Mi 0.08%

TABLE X Equipment used Pump “Rice test” Chamber Pressure pirani gage #2Empty Chamber Conditions of Pumping by the top experiment Pressuremeasurement by the side Pressure Measurement P1 chambre (torr) t (s)

0 800 5 540 10 35 20 5.6 30 4.2 40 4 50 4 60 4 70 4 80 4 90 4 100 4 1104 120 4

TABLE XI Equipment used Pump “Rice test” Chamber Pressure pirani gage #2Water in cup Conditions of Pumping by the top experiment Pressuremeasurement by the side Pressure Measurement t (s) P1 chambre (torr)

0 800 5 300 10 46 20 12 30 8 40 6.2 50 5.8 60 5.8 70 5.8 80 5.8 90 5.8100 5.8 110 5.8 120 5.8

TABLE XII Equipment used Pump “Rice test” Chamber Pressure pirani gage#2 Water in sponge Conditions of Pumping by the top experiment Pressuremeasurement by the side Pressure Measurement t (s) P1 chambre (torr)

0 800 5 260 10 50 20 13 30 9.5 40 7 50 6.4 60 6.4 70 6.4 80 6.4 90 6.4100 6.4 110 6.4 120 6.4

TABLE XIII Equipment used Pump “Rice test” Chamber Pressure pirani gage#2 Small asphalt puck Conditions of Pumping by the top experimentPressure measurement by the side Pressure Measurement t (s) P1 chambre(torr)

0 800 5 150 10 44 20 14 30 11 40 9.7 50 8 60 7.4 70 7 80 7 90 7 100 7110 7 120 7 150 7 180 7 220 7 Minitial (g) 1098 Mfinal (g) 1095.7 % loss0.21%

TABLE XIV Equipment used Pump “Rice test” Chamber Pressure pirani gage#2 Small concrete puck Conditions of Pumping by the top experimentPressure measurement by the side Pressure Measurement t (s) P1 chambre(torr) 

  0 800 5 230 10 46 20 16 30 13 40 11 50 9 60 8.5 70 8 80 8 90 7.8 1007.8 110 7.8 120 7.8 150 7.8 180 7.8 220 7.8 Minitial (g) 983.8 Mfinal(g) 980.1 % loss 0.38%

TABLE XV Equipment used Pump “Rice test” Chamber Pressure pirani gage #2Big concrete puck Conditions of Pumping by the top experiment Pressuremeasurement by the side Pressure Measurement t (s) P1 chambre (torr) 

0 800 5 120 10 29 20 18 30 14 40 11 50 10 60 9 70 9 80 9 90 8.5 100 8.5110 8.5 120 8.5 150 8.5 180 8.5 220 8.5 Minitial (g) 4822.6 Mfinal (g)4819.7 % loss 0.06%

TABLE XVI Equipment used Pump “Rice test” Chamber Pressure pirani gage#2 Microwave Desiccant Empty Chamber Conditions of Pumping by the topexperiment Pressure measurement by the top Schematic drawing: FIG. 9Pressure Measurement t (s) P1 chambre (torr) 

10 400 20 110 30 70 40 42 50 29 60 20 70 15 80 12 90 10 100 8.5 110 7120 6.4 130 5.6 140 5.2 150 4.6 160 4.2 170 3.8 180 3.5 190 3.3 200 3210 2.8 220 2.8 230 2.5 240 2.4

TABLE XVII Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Desiccant 10 gram of water in cup Conditionsof Pumping by the top experiment Pressure measurement by the topSchematic drawing: FIG. 9 Pressure Measurement t (s) P1 chambre (torr) 

10 110 20 80 30 70 40 48 50 40 60 30 70 32 80 36 90 29 100 35 110 40 12033 130 29 140 24 150 23 160 21 170 20 180 20 190 19 200 19 210 17 220 17230 15 240 15

TABLE XVIII Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Desiccant Small asphalt puck Conditions ofPumping by the top experiment Pressure measurement by the top Schematicdrawing: FIG. 9 Pressure Measurement t (s) P1 chambre (torr) 

0 800 5 440 10 280 20 100 30 68 40 40 50 21 60 15 70 11 80 9.5 90 8 1007.4 110 7.4 120 6.8 130 6.8 140 6.8 150 6.6 160 6.6 170 6.6 180 6.6 1906.6 200 6.6 210 6.6 220 6.6 230 6.6 240 6.6 Minitial (g) 1110.8 Mfinal(g) 1110.5 % loss 0.03%

TABLE XIX Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Desiccant Small asphalt puck Conditions ofPumping by the top experiment Pressure measurement by the top Schematicdrawing: t (s) P1 chambre (torr) 

FIG. 9  10 370 Pressure Measurement  20 110 Minitial (g) 1109.6  30  80Mfinal (g) 1098  40  74 % loss 1.05%  50  62  60  40  70  33  80  29  90 28 100  32 110  34 120  35 130  38 140  40 150  42 160  42 170  46 180 46 190  46 200  50 210  56 220  56 230  56 240  56 270  48 300  52 330 58 360  62 390  54 420  48 450  46 480  44 510  42 540  40

TABLE XX Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Desiccant Small asphalt puck Schematicdrawing: t (s) P1 chambre (torr) 

FIG. 9 10 460 Pressure Measurement 20 240 Minitial (g) 1103.1 30 100Mfinal (g) 1096.7 40 70 % loss 0.58% 50 40 Conditions of experiment 6023 Pumping by the top 70 17 Pressure measurement by the top 80 17 90 16100 17 110 17 120 17 130 18 140 20 150 20 160 20 170 20 180 22 190 22200 24 210 27 220 27 230 30 240 32 270 32 300 28 330 23 360 20 390 19420 17 450 16 480 14 510 14 540 13 570 12 600 11

TABLE XXI Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Water filter as cold trap Empty ChamberConditions of Pumping by the top experiment Pressure measurement by thetop Schematic drawing: FIG. 8 Pressure Measurement t (s) P1 chambre(torr) 

10 14 20 4.4 30 3.4 40 2.6 50 2 60 1.8 70 1.7 80 1.1 90 1.1 100 1.1 1101 120 0.9 130 0.9 140 0.85 150 0.85 160 0.8 170 0.8 180 0.85 190 0.85200 0.85 210 0.8 220 0.8 230 0.8 240 0.8 270 0.85 300 0.8 330 0.76 3600.76 390 0.78 420 0.8 450 0.8

TABLE XXII Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Water filter as cold trap Small asphalt puckConditions of Pumping by the top experiment Pressure measurement by thetop Schematic drawing: FIG. 8 Pressure Measurement t (s) P1 chambre(torr) 

0 800 5 100 10 13 20 7 30 6.2 40 6 50 5.8 60 5.8 70 5.8 80 5.8 90 5.8100 5.8 110 5.8 120 5.8 130 5.8 140 5.6 150 5.6 160 5.6 170 5.6 180 5.6190 5.6 200 5.6 210 5.4 220 5.4 230 5.4 240 5 270 4.8 Minitial (g)1099.3 Mfinal (g) 1095.6 % loss 0.34%

TABLE XXIII Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Water filter as cold trap Small asphalt puckConditions of Pumping by the top experiment Pressure measurement by thetop Schematic drawing: t (s) P1 chambre (torr) 

FIG. 8  0 800 Pressure Measurement  5 100 Minitial (g) 1100  10 10Mfinal (g) 1095.6  20 6.2 % loss 0.40%  30 5.8  40 5.6  50 5.6  60 5.6 70 5.6  80 5.4  90 5.4 100 5.4 110 5.4 120 5.4 130 5.4 140 5.4 150 5.2160 5.2 170 5.2 180 5.2 190 5.2 200 5.2 210 5 220 5 230 5 240 4.8 2704.6 300 4.4 330 4.2 360 4 390 4 420 4

TABLE XXIV Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Water filter as cold trap Small concrete puckConditions of Pumping by the top experiment Pressure measurement by thetop Schematic drawing: t (s) P1 chambre (torr) 

FIG. 8  0 800 Pressure Measurement  5 100 Minitial (g) 988.8  10 18Mfinal (g) 982.4  20 7.5 % loss 0.65%  30 5.6  40 5.4  50 5.4  60 5.2 70 5.2  80 5.2  90 5.2 100 5.2 110 5.2 120 5.2 130 5.2 140 5.2 150 5.2160 5.2 170 5.2 180 5.2 190 5.2 200 5.2 210 5.4 220 5.4 230 5.4 240 5.4270 5.4 300 5.4 330 5.4 360 5.6 390 5.6 420 5.6

TABLE XXV Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Water filter as cold trap Small asphalt puckSchematic drawing: t (s) P1 chambre (torr) 

FIG. 9  10 11 Pressure Measurement  20 5.4 Minitial (g) 1101.4  30 3.9Mfinal (g) 1095.4  40 3.6 % loss 0.54%  50 3.4 Conditions of experiment 60 3 Pumping by the top  70 3.2 Pressure measurement  80 3.3 by the top 90 3.4 100 3.5 110 3.7 120 3.8 130 3.9 140 3.9 150 4 160 4 170 4.6 1804.6 190 4.6 200 4.8 210 4.8 220 4.8 230 4.8 240 4.8 270 5.2 300 5.2 3305.2 360 5.4 390 5.4 420 5.4 450 5.6 480 5.6 510 5.6 540 5.6 570 5.6 6005.6

TABLE XXVI Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Water filter as cold trap Small asphalt puckConditions of Pumping by the top experiment Pressure measurement by thetop Schematic drawing: t (s) P1 chambre (torr) 

FIG. 8 0 800 Pressure Measurement 5 100 10 76 20 8 30 5.8 40 5.6 50 5.660 5.6 70 5.6 80 5.6 90 5.6 100 6 110 6 120 5.8 130 5.8 140 5.8 150 6160 5.8 170 5.8 180 6 190 6 200 6 210 6 220 5.8 230 6 240 6 270 5.8 3005.4 330 5.8 360 5 390 4.8 420 4.2 450 4.4

TABLE XXVII Equipment used Pump + Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave + Water filter as cold trap Small asphalt puckConditions of Pumping by the top experiment Pressure measurement by thetop Schematic drawing: t (s) P1 chambre (torr) 

FIG. 8 0 800 Pressure Measurement 5 100 10 10 20 9 30 5.8 40 5.4 50 5.460 5.2 70 5.2 80 5.4 90 5.4 100 5.4 110 5.2 120 5.2 130 5.2 140 5.2 1505.2 160 5 170 4.8 180 4.8 190 4.8 200 4.8 210 4.6 220 4.2 230 4.2 2404.2 270 4 300 3.6 330 3.3 360 3.2 390 2.8 420 2.6

TABLE XXVIII Pump FIG. 8 System Plexiglas cylindrical chamber Pressurepirani gage #2 Microwave Water filter as cold trap Small Asphalt Puck,Fine aggregate Final Temperature (° C.) 27-28° C. Initial Temperature (°C.) 23° C. M(g) Mwet Mdry 1096.8 1104.1 1097.6 Initial water content (g)7.3 Final water content (g) 0.8 Small Asphalt Puck, Coarse aggregateFinal Temperature (° C.) 35-37° C. Initial Temperature (° C.) 23° C.M(g) Mwet Mdry 1389.0 1395.1 1388.8 Initial water content (g) 6.1 Finalwater content (g) 0.2 Big Asphalt Puck 1 Final Temperature (° C.) 45-50°C. Initial Temperature (° C.) 23° C. M(g) Mwet Mdry 4817.0 4822.0 4817.5Initial water content (g) 5 Final water content (g) 0.5 Big Asphalt Puck2 Final Temperature (° C.) 30-32° C. Initial Temperature (° C.) 23° C.M(g) Mwet Mdry 4736.9 4773.9 4743.6 Initial water content (g) 37 Finalwater content (g) 6.7Protocol of Experimentation:

In the one or more experiments that follow, testing for a puck wasperformed. In the experiment, air (ambient) was vacuumed out of thechamber of FIG. 8 until between 7 and 11 Torr was reached during thefirst two minutes. Vacuum was then applied until a pressure of about 20Torr was reached for one minute while heating with microwave. Themicrowave was then turned off, and vacuum forces were applied for oneminute. This cycle was repeated until the total cycle time was eight (8)minutes. The experimental setup

TABLE XXIX Pump Plexiglas cylindrical chamber Pressure pirani gage #2Microwave Water filter as cold trap FIG. 8 System Initial Final Temp-Water Water M Mwet Mdry erature content content Puck Test (g) (g) (g) (°C.) (g) (g) Small. 1 1095.4 1098.7 1095.7 34-36 3.3 0.3 made of 2 1095.41099.1 1095.7 30-31 3.7 0.3 ′Fine′ 3 1095.4 1099.6 1095.6 39-40 4.2 0.2Aggregates 4 1095.4 1099.8 1095.6 38-40 4.4 0.2 Small. 1 1389 1394.61389.2 27-29 5.6 0.2 made of 2 1389 1394.1 1389.1 36-38 5.1 0.1 ′Coarse′3 1389 1394 1389 26-29 5 0 Aggregates 4 1389 1395.3 1389 33-35 6.3 0Big. made 1 4817.4 4821 4817.4 28-30 3.6 0 of ′Fine′ 2 4817.4 4821.34817.4 33-35 3.9 0 Aggregate 3 4817.4 4821.3 4817.2 38-40 3.9 −0.2 44817.4 4821.4 4817.3 35-37 4 −0.1 Big. made 1 4737.2 4764.5 4737.2 34-3527.3 0 of ′Coarse′ 2 4737.2 4765.1 4737.9 34-37 27.9 0.7 Aggregate 34737.2 4771.2 4738.3 28-30 34 1.1

TABLE XXX Pump Rice Test chamber FIG. 6 System Pressure pirani gage #2Cycle of Pressure application Microwave (vacuum), then microwave for oneWater filter as cold trap minute each for an eight minute cycle InitialFinal Final Absorption mass Initial mass Water [Mwet-Mdry]/ Puck Test(g) Absorption (g) content Mdry SAND 1 250.2 8% 241.6 8.6 3.44% 2 239.111.1 4.44% 3 236.3 13.9 5.55% 4 232.2 18 7.19% 5 7.51% 6 7.59% 7 7.59%FRANKEN 1 283.1 8% 271.7 11.7  4.1% SOIL 2 264.8 18.5 6.53% 3 261.7 21.67.63% 4 261.7 21.6 7.63%

TABLE XXXI Pump Rice Test chamber FIG. 6 System Pressure pirani gage #2Cycle of Pressure application Microwave (vacuum), then microwave for oneWater filter as cold trap minute each for an eight minute cycleTemperature Initial Final M Mwet Mdry (° C.) Water Water Puck (g) (g)(g) Initial/Final content (g) content (g) Small. 1095.2 1100.3 1095.7 2135-40 5.1 0.5 ′Fine′ Aggregates Small. 1389.1 1394.5 1389.3 21 32-35 5.40.2 ′Coarse′ Aggregates Big. ′Fine′ 4817.3 4821.6 4817.6 20 34-36 4.30.3 Aggregate Big. 4735.9 4775.9 4756.4 20 35-37 40 20.5 ′Coarse′Aggregate

While the embodiments have been described in connection with thepreferred embodiments of the various figures, it is to be understoodthat other similar embodiments may be used or modifications andadditions may be made to the described embodiment for performing thesame function without deviating therefrom. Therefore, the disclosedembodiments should not be limited to any single embodiment, but rathershould be construed in breadth and scope in accordance with the appendedclaims.

What is claimed:
 1. A method for drying at least one sample of materialusing a small portable field device, the method comprising: placing asample of a road construction related material into an interior of achamber; placing the chamber with the sample therein into a heatingdevice; applying a vacuum to regulate pressure of the interior of thechamber; applying heating to the sample using the heating device toregulate a temperature of the sample at a substantially constantregulated temperature while applying the vacuum to the interior of thechamber; and determining that the sample is dry based on the at leastone monitored condition.
 2. The method of claim 1, wherein the samplehas a mass less than 4.5 kg.
 3. The method of claim 1, wherein theheating device comprises a quick-release vacuum hookup, and wherein themethod comprises coupling the chamber to the hookup before applying thevacuum.
 4. The method of claim 1, wherein the heating device comprisesmultiple quick-release vacuum hookups, and the method comprises: placingmultiple samples of a road construction related material into therespective interiors of multiple chambers; placing the chambers with thesamples therein into a heating device; applying respective vacuums toregulate the respective pressures of the interiors of the chambers. 5.The method of claim 1, wherein applying heating to the sample using theheating device comprises applying microwave energy to the sample.
 6. Themethod of claim 1, wherein the regulated temperature is above or aboutroom temperature.
 7. The method of claim 1, further comprising filteringmoisture from air evacuated from the chamber during at least a portionof the applying the vacuum.
 8. The method of claim 1, wherein the atleast one sample of material is at least one compacted asphalt sample,loose asphalt mix, and loose aggregate.
 9. The method of claim 1,wherein the vacuum is applied by a vacuum pump, and wherein thetemperature of the sample and the pressure of the interior of thechamber are regulated in concert to maximize mass transfer with thevacuum pump.
 10. The method of claim 1, wherein monitoring the at leastone condition comprises monitoring pressure of the sealed chamber. 11.The method of claim 1, wherein the monitoring the at least one conditioncomprises monitoring infrared radiation.
 12. A field portable system fordrying a sample of material, the system comprising: a sealable chamberincluding an interior sized and configured to house the sample ofmaterial, wherein the sample is a construction material from a roadsurface or material for use as a road surface, the chamber including anoutlet; a vacuum pump in fluid communication with the chamber toevacuate air from the interior of the chamber through the outlet of thechamber thereby regulating a pressure of the interior of the chamber; anelectromagnetic wave source in communication with the chamber; and atleast one controller configured to: operate the vacuum pump and theelectromagnetic wave source; start and stop a drying operation using thevacuum pump and the electromagnetic wave source; monitor pressure andinfrared radiation in the interior of the chamber; and determine thatthe at least one sample of material is dry based on the monitoredpressure and infrared radiation, wherein heating is carried out byautomatically adjusting the energy of the electromagnetic wave source toregulate a temperature of the at least one sample in concert withregulating the pressure of the interior of the chamber.
 13. The fieldportable system of claim 12, further comprising a first valve positionedbetween the vacuum pump and the chamber and a second valve in fluidcommunication with the chamber and configured to introduce atmosphericair to the interior of the chamber when open, wherein the controller isconfigured to open and close the first and second valves.
 14. The fieldportable system of claim 13, wherein, during the drying operation: thevacuum pump is on; the first valve is open; the second valve is closed;and the electromagnetic wave source is operated to maintain the interiorof the chamber at about room temperature.
 15. The field portable systemof claim 14, further comprising a lid for sealably closing the chamberduring the drying operation, wherein the first valve is closed and thesecond valve is open after the drying operation to allow the lid to beremoved and the at least one dry sample to be accessed.
 16. The fieldportable system of claim 12, further comprising a moisture trappositioned between the vacuum pump and the chamber to filter moisturefrom the evacuated air during the drying operation.
 17. The fieldportable system of claim 12, further comprising at least one evaporatorplate positioned below the sample and configured to provide thermalenergy to evaporate residual water within the chamber during the dryingoperation.
 18. The field portable system of claim 12, further comprisinga pressure sensor configured to detect the pressure inside the chamberand an infrared radiation sensor configured to detect the infraredradiation inside the chamber.
 19. The field portable system of claim 12,wherein the temperature of the sample and the pressure of the interiorof the chamber are regulated in concert to maximize mass transfer withthe vacuum pump.
 20. The field portable system of claim 12, wherein theinterior of the chamber is sized and configured to house a sample havinga mass less than 4.5 kg.